The interval times can catch you out as well.
In theory, most laptop related stuff (lead, ac adapter etc) are subject to annual inspection, when in an office environment.
but when you then take that stuff to a building/mining site... it
can come under quarterly.
This is open to interpretation... one could argue that the laptop lead
should only be annual, but we've had equipment that was in test as annual and a Jobsworth at a site refused it as it wasn't in quarterly test.

(Just to add insult, it was last tested within the quarterly date anyway, just wasn't the right colour tag.)
That said, I've been to the site offices of some of the major industry players and stuff was out of test, by years in some cases.
Contractors, do what their told; The big boys, do what they want.
So we mostly test quarterly for items that go out of the office, in case they
may be refused as the downtime, airfares etc just aren't worth it.